Light-emitting device

ABSTRACT

This disclosure discloses a light-emitting device, comprising a substrate having a first major surface and a second major surface; a plurality of light-emitting stacks on the first major surface; and at least one electronic device on the second major surface, wherein the light-emitting stacks are electrically connected to each other in series via a first electrical connecting structure; the electronic device are electrically connected to the light-emitting stacks via a second electrical connecting structure.

REFERENCE TO RELATED APPLICATION

The application claims the right of priority based on TW applicationSer. No. 098123043 filed on Jul. 7, 2009, which is incorporated hereinby reference and assigned to the assignee herein.

TECHNICAL FIELD

The application relates to a light-emitting device, and moreparticularly to a light-emitting device comprising a substrate having afirst major surface and a second major surface. A plurality oflight-emitting stacks are on the first major surface, and at least oneelectronic device is on the second major surface, wherein thelight-emitting stacks are electrically connected to the electronicdevice.

DESCRIPTION OF BACKGROUND ART

The light-emitting mechanism of the light-emitting diode is to takeadvantage of the energy difference of electrons between the n-typesemiconductor and the p-type semiconductor and then to release theenergy in the form of light, which is different from the light-emittingmechanism of the incandescent lamp, which is by heating. Therefore, thelight-emitting diode is called the cold light source. Besides, thelight-emitting diode has the advantages such as long endurance, longlifetime, light weight, and low power consumption. Therefore, thepresent illumination market expects the light-emitting diode as a newgeneration illumination to substitute for the traditional light sourceand apply it to various fields such as traffic signal, backlight module,street light, and medical apparatus.

FIG. 1 is the illustration of a conventional AC light-emitting diodedevice. As shown in FIG. 1, the light-emitting device 100 comprises asubstrate 10, a plurality of light-emitting units 12 disposing on thesubstrate 10 and are serially connected to form circuit A and circuit Bthat are anti-parallel connected to each other later, and two electrodes14 and 16 disposing on the substrate 10 and electrically connecting tothe plurality of the light-emitting units 12. When the alternativecurrent flows into the light-emitting device 100 through the electrode14, the current passes through circuit A and triggers the light-emittingunit 12 in the circuit A to emit light. Correspondingly, when thealternative current flows into the light-emitting device 100 through theelectrode 16, the current passes through circuit B and triggers thelight-emitting unit 12 in the circuit B to emit light.

Besides, the light-emitting device 100 could form a photoelectricapparatus by further connecting with other components. FIG. 2 is theillustration for the conventional photoelectric apparatus. As shown inFIG. 2, a photoelectric apparatus 200 comprises a sub-mount 20, whichcomprises at least one circuit 202; a solder 22 located on the sub-mount20 to attach the light-emitting device 100 on the sub-mount 20 and toelectrically connect the substrate 10 of the light-emitting device 100with the circuit 202 on the sub-mount 20; and one electricallyconnecting structure 24 electrically connecting the electrode 16 of thelight-emitting device 100 and the circuit 202 on the sub-mount 20. Thesub-mount 20 comprises a lead frame or a large-size mounting substrateto facilitate the circuit arrangement and to raise the heat dissipatingefficiency.

Nevertheless, although the design of the light-emitting device 100 couldbe applied to the alternative current directly, only parts of thelight-emitting units 12 emitting light at the same time often causes thewaste of the light-emitting area on the light-emitting device.

SUMMARY OF THE DISCLOSURE

The present disclosure provides a light-emitting device comprising asubstrate having a first major surface and a second major surface; aplurality of light-emitting stacks spacing at intervals mutually on thefirst major surface, wherein the light-emitting stacks electricallyconnecting to each other via the first electrical connecting structure;and at least one electronic device on the second major surfaceelectrically connecting to the light-emitting stacks via a secondelectrical connecting structure extending from the first major surfaceto the second major surface of the substrate.

The present disclosure also provides a light-emitting device comprisinga substrate having a first major surface and a second major surface; aplurality of light-emitting stacks on the first major surface; and atleast one bridge rectifying device and one passive device on the secondmajor surface, wherein the light-emitting stacks and the bridgerectifying device are electrically connected to each other.

The present disclosure further provides a light-emitting devicecomprising a substrate, wherein a plurality of light-emitting stacks andat least one electronic device disposed on a first major surface and asecond major surface of the substrate respectively, and the pluralitylight-emitting stacks on the first major surface and the electronicdevice on the second major surface electrically connecting to each othervia a plug of the substrate or via the metal wire.

The present disclosure further provides a light-emitting devicecomprising a substrate, wherein a plurality of light-emitting stacks andat least one electronic device disposed on the top-side surface and thebottom-side surface respectively, and further comprising a heatdissipation layer located on the bottom-side surface of the substrate toraise the heat dissipating efficiency and to increase the reliability ofthe light-emitting device.

The present disclosure further provides a light-emitting devicedisposing the devices such as the electric device like the rectifyingdevice, the resistance, the inductance, and the capacitance or the heatdissipation layer that are not for light emitting on the second majorsurface of the substrate and to dispose the light-emitting stacks on thefirst major surface. Such design uses the total surface where thelight-emitting stacks located on to be the light extraction surface andreduce the waste of light-emitting area.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is the illustration of the conventional light-emitting device.

FIG. 2 is the illustration of the conventional photoelectric apparatus.

FIG. 3A is the side view illustration in accordance with one embodimentin the present disclosure.

FIG. 3B is the circuit illustration of the present disclosure.

FIGS. 4A and 4B are the illustrations of the first electrical connectingstructure in accordance with one embodiment in the present disclosure.

FIGS. 5A and 5B are the illustrations of the second electricalconnecting structure in accordance with one embodiment in the presentdisclosure.

FIG. 6 is the top view and the bottom view in accordance with oneembodiment in the present disclosure.

FIG. 7 is the illustration of the fourth electrical connecting structurein accordance with one embodiment in the present disclosure.

FIG. 8 is the illustration in accordance with another embodiment in thepresent disclosure.

FIG. 9 is the illustration in accordance with another embodiment in thepresent disclosure.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The following shows the description of the embodiments of the presentdisclosure in accordance with the drawings.

FIG. 3A is the side view illustration in accordance with one embodimentin the present disclosure and FIG. 3B is the circuit illustration inaccordance with one embodiment of the present disclosure. As shown inFIGS. 3A and 3B, the light-emitting device comprises a substrate 30having a first major surface 302 and a second major surface 304; aplurality of light-emitting stacks 32 spacing at intervals mutually onthe first major surface 302, wherein the light-emitting stacks 32electrically connecting to each other via a plurality of the firstelectrical connecting structures 320; and at least one rectifying device34 locating on the second major surface 304 of the substrate 30, whereinthe rectifying device 34 having a plurality of semiconductor stacks 340,which are electrically connecting to each other via a second electricalconnecting structure 342 and arranging in a bridge circuit form.Besides, the light-emitting stacks 32 electrically connect to therectifying device 34 by the first electrical connecting structure 36.

Besides, the light-emitting device 300 further comprises at least onebump pad 38, which is electrically connecting to the rectifying device34 and the AC power supplier (not shown in the figure) respectively,located on the second major surface 304. When the alternative currentflows into the light-emitting device 300 via the bump pad 38, thecurrent is converted into a direct current by passing through the bridgerectifying circuit, which is arranged by the plurality of thesemiconductor stacks 340 located on the second major surface 304, andthen the current is transmitted to the light-emitting stacks through thethird electrical connecting structure 36, wherein the third electricalconnecting structure 36 comprises the metal plug filled in the via holepassing through the substrate 30, or the conductive wire extending fromthe first major surface 302 to the second major surface 304.

In the light-emitting device 300, the materials of the substrate 30comprise the insulating materials such as sapphire, aluminum nitride(AIN), glass, or diamond. The substrate 30 can also be a single layerstructure formed by a single material. The substrate 30 in theembodiment is a single layer substrate made of sapphire. Thelight-emitting stacks 32 comprise one first conducting typesemiconductor layer 322 formed on the substrate 30, a light emittinglayer 324 formed on the first conducting type semiconductor layer 322,and a second conducting type semiconductor layer 326 formed on the lightemitting layer 324, wherein the materials of the light-emitting stacks32 comprise semiconductor materials containing aluminum (Al), gallium(Ga), indium (In), nitrogen (N), phosphor (P), and/or arsenic (As), suchas the Gallium Nitride (GaN) series materials or the Aluminum GalliumIndium Phosphide (AlGaInP) series materials. In the embodiment, thelight-emitting stacks 32 are formed by the metal-organic chemical vapordeposition, and each light-emitting stack 32 comprises a partiallyexposed first conducting type semiconductor layer 322 formed byphotolithography and the etching technology. The first electricalconnecting structure 320 serially connects to the first conducting typesemiconductor layer 322 of the light emitting stack 32 and the secondconducting type semiconductor layer 326 of the adjacent light emittingstack 32 respectively.

Furthermore, the semiconductor stacks 340 for composing the rectifyingdevice 34 comprise a plurality of the structures such as thelight-emitting diode, the Zener diode, or the Schottky diode formed bythe metal-organic chemical vapor deposition, the photolithography andthe etching technology, and the materials comprise the III-V compoundsor the Group IV elements such as the Gallium Nitride (GaN) seriesmaterials, the Aluminum Gallium Indium Phosphide (AlGaInP) seriesmaterials, or Silicon.

As shown in FIG. 4A, the first electrical connecting structure 320comprises an insulating layer 3202 filled between the adjacentlight-emitting stacks 32 to prevent the short circuit between theadjacent light-emitting stacks 32 and a metal layer 3204 that is locatedon the insulating layer 3202 and electrically connecting to the adjacentlight-emitting stacks 32. Besides, the first electrical connectingstructure 320 could also be a metal wire as shown in FIG. 4B, and thetwo terminals of the metal wire are connected to the adjacentlight-emitting stacks 32 respectively. The second electrical connectingstructure 342 comprises an insulating layer 3422 filled between theadjacent semiconductor stacks 340 to prevent the short circuit betweenthe connecting semiconductor stacks 340 and a metal layer 3424 that islocated on the insulating layer 3422 and electrically connecting to theadjacent semiconductor stacks 340. Besides, the second electricalconnecting structure 342 can also be a metal wire as shown in FIG. 5B,and the two terminals of the metal wire are connected to the adjacentsemiconductor stacks 340 respectively.

FIG. 6 is the illustration of another embodiment. The light-emittingstacks 32 and the semiconductor stacks 340 of the light-emitting device300 can be formed on the first major surface 302 and the second majorsurface 304 by the metal-organic chemical vapor deposition, thephotolithography and the etching technology. Besides, an adhesive layer44 can also be provided between the light-emitting stacks 32, thesemiconductor stacks 340 and the substrate 30 to attach thelight-emitting stacks 32 and the semiconductor stacks 340 to the firstmajor surface 302 and the second major surface 306 of the substrate 30respectively. The yield of the products is therefore increased and theproduction cost is reduced. The material of the adhesive layer 44comprises the metal material or the organic adhesive material.

FIG. 7 is the illustration of another embodiment. As shown in FIG. 7,the light-emitting device 300 further comprises a passive device 40located on the second surface 304 of the substrate 30 and electricallyconnecting to the rectifying device 34. For example, the passive device40 comprises a resistance, an inductance, or a capacitance seriallyconnecting to the rectifying device 34, or a capacitance parallellyconnecting to the rectifying device 34 to provide the electricprotection for the light-emitting device 300 or to adjust the electriccharacteristic of the light-emitting device 300. The passive device canbe a thin-film resistance, a thin-film capacitance, or a thin-filminductance integrated with the light-emitting device 300 as a singlechip, and the material of the above mentioned thin-film resistancecomprises tantalum nitride (TaN), silicon-chromium alloy (SiCr), ornickel-chromium alloy (NiCr).

FIG. 8 is the illustration of another embodiment. As shown in FIG. 8,the light-emitting device 300 further comprises a wavelength convertingstructure 42 located on the light-emitting stacks 32 to absorb andconvert the light emitted from the light-emitting stacks 32. Wherein,the material of the wavelength comprises one or more than onefluorescent materials or phosphor materials, and the wavelengthconverting structure 42 can be a layer structure uniformly coated on thelight-emitting stacks 32 or a glue comprising the fluorescent materialto encapsulate the light-emitting stacks so the products with differentoptical properties are formed.

FIG. 9 is the illustration of another embodiment. As shown in FIG. 9,the light-emitting device 300 further comprises a heat dissipation layer46, wherein the heat dissipation layer 46 can connect with the secondmajor surface 304 of the substrate 30 or the passive device 34 to guidethe heat produced from the elements in the light-emitting device 300.Besides, the material of heat dissipation layer 46 has high thermalconductivity which is preferably larger than that of the substrate 30 orlarger than 50 W/mK. The material of the heat dissipation layer 46 canbe copper, silver, gold, nickel, diamond, diamond-like carbon (DLC),aluminum nitride (AIN), graphite, carbon nanotube (CNT), or thecomposite thereof. The thickness of the heat dissipation layer ispreferably larger than 3 μm and the area of it is preferably not smallerthan 30% of that of the substrate 30.

Furthermore, the light-emitting devices 300 as shown in FIG. 3A to FIG.9 can be applied to the lighting system, and the lighting system can befurther applied to the illumination system, the display backlightmodule, or the vehicle lighting, and the light-emitting devices 300 canbe adapted to the power supply with 100V, 110V, 220V, 240V, 12V, 24V, or48V.

The present disclosure discloses the light-emitting device 300 disposingthe device such as the rectifying device 34, the bump pad 38, theresistance, the inductance, the capacitance, and the heat dissipationlayer 46 that are not for light emitting on the second major surface 304of the substrate 30 and to dispose the light-emitting stacks 32 on thefirst major surface 302 of the substrate 30. Such design uses the totalsurface where the light-emitting stacks 32 located on the light-emittingdevice 300 to be the light extraction surface and reduces the waste oflight-emitting area.

The embodiments mentioned above are used to describe the technicalthinking and the characteristic of the invention and to make the personwith ordinary skill in the art to realize the content of the inventionand to practice, which could not be used to limit the claim scope of thepresent invention. That is, any modification or variation according tothe spirit of the present invention should also be covered in the claimscope of the present disclosure.

1. A light-emitting device, comprising: a substrate, comprising a firstmajor surface and a second major surface; a plurality of light-emittingstacks located on the first major surface of the substrate, wherein thelight-emitting stacks electrically connecting to each other via a firstelectrical connecting structure; at least one electronic device locatedon the second major surface of the substrate; and a second electricalconnecting structure extending from the first major surface to thesecond major surface of the substrate and electrically connecting thelight-emitting stacks and the electronic device.
 2. The light-emittingdevice of claim 1, wherein the electronic device comprising aresistance, an inductance, capacitance, or a rectifying device.
 3. Thelight-emitting device of claim 2, wherein the rectifying devicecomprising a plurality of semiconductor stacks.
 4. The light-emittingdevice of claim 1, wherein the first electrical connecting structurecomprising a metal wire or a metal plug passing through the substrate.5. The light-emitting device of claim 3, wherein the semiconductorstacks form a light-emitting diode, a Zener diode, or a Schottky diode.6. The light-emitting device of claim 1, further comprising a wavelengthconverting layer covering on the light-emitting stacks, wherein thematerial of the wavelength converting layer comprising a fluorescentmaterial or a phosphor material.
 7. The light-emitting device of claim2, wherein the material of the resistance comprising tantalum nitride(TaN), silicon-chromium alloy (SiCr), or nickel-chromium alloy (NiCr).8. The light-emitting device of claim 1, further comprising a heatdissipation layer on the second major surface of the substrate, whereinthe heat dissipation layer comprising a thermal conductivity larger than50 W/mK.
 9. The light-emitting device of claim 8, wherein the thicknessof the heat dissipation layer is larger than 3 μm or the area of theheat dissipation layer is not smaller than 50% of that of the substrate.10. The light-emitting device of claim 8, wherein the material of theheat dissipation layer comprising copper, silver, gold, nickel, diamond,diamond-like carbon (DLC), aluminum nitride (AIN), graphite, carbonnanotube (CNT), or the composite thereof
 11. The light-emitting deviceof claim 1, further comprising an adhesive layer located between thelight-emitting stacks and the substrate and/or between the electronicdevice and the substrate, wherein the material of the adhesive layercomprising a metal material or an organic adhesive material.
 12. Thelight-emitting device of claim 1, wherein the substrate is a singlelayer structure.
 13. The light-emitting device of claim 1, which isadapted to the power supply with 100V, 110V, 220V, 240V, 12V, 24V, or48V.
 14. A light-emitting device, comprising: a substrate, comprising afirst major surface and a second major surface; a plurality oflight-emitting stacks, located on the first major surface of thesubstrate; and one bridge rectifying device and one passive device,located on the second major surface of the substrate, wherein thelight-emitting stacks, the bridge rectifying device, and the passivedevice are electrically connected to each other.
 15. The light-emittingdevice of claim 14, wherein the passive device comprising a thin-filmresistance, a thin-film inductance, or a thin-film capacitance.
 16. Thelight-emitting device of claim 14, further comprising an adhesive layerlocated between the light-emitting stacks and the substrate and/orbetween the passive device, the bridge rectifying device and thesubstrate, wherein the material of the adhesive layer comprising a metalmaterial or an organic adhesive material.
 17. The light-emitting deviceof claim 14, wherein the substrate is a single layer structure.
 18. Thelight-emitting device of claim 14, which is adapted to the power supplywith 100V, 110V, 220V, 240V, 12V, 24V, or 48V.